Frenchman’s Creek Restoration

Frenchmen’s Creek is a perennial coastal stream located in Half Moon Bay on the Central Coast of California. The stream is approximately 4.1 miles long and drains directly to the Pacific Ocean. The stream and riparian corridor are relatively undisturbed and intact, providing good habitat for coast steelhead and other riparian wildlife. In the early 1970’s the landowner installed a six-foot diameter by 42-foot long culvert to provide a farm road crossing across the creek. Over time, the culvert become perched, and the invert elevation of the culvert outlet was approximately nine feet above the bed of the channel. The condition created a barrier to the passage of both juvenile and adult steelhead and did not allow fish to access the upper one and half mile of stream course. Sherwood (operating as Fall Creek Engineering) was retained by the San Mateo County Resource Conservation District and led a multi-disciplinary team of engineers, scientist and biologist to remove the culvert and restore the stream for juvenile and adult fish passage. The perched culvert was replaced with a 65 long railcar bridge. The project included several biotechnical stream channel and bank stabilization measures to restore the channel to a stable, non-eroding condition. Eight one-foot high boulder step-pool weirs were installed to provide grade control and facilitate step-pool formation to enhance fish passage and habitat in the project reach.